Elbow-Joint. 



95 



ConHylus 

 externus 



.rt. Jiumero- 

 ulnaris 



118. The Eight Elbow- Joint, Articulatio cubit?] 



from before. 



The elbow-joint is formed by three bones: the humerus, ulna 

 and radius ; it consists of three portions, and these are : 



1. the Articulatio humero-ulnaris, formed above by the trochlea of the 

 humerus and below by the greater sigmoid cavity of the ulna (flexion - 

 extension) ; 



2. the Articulatio humero-radialis, formed above by the lesser or radial 

 head (Emimntia capitata) of the humerus, and below by the cup -shaped 

 depression on the head of the radius (flexion extension) ; 



3. the Articulatio radio-ulnaris superior, formed externally by the cir- 

 cumference of the head of the radius, Capitulum radii, and internally by 

 the lesser sigmoid cavity of the ulna (pronation - - supination). 



